Snubber for a dipper door

ABSTRACT

A linkage assembly is provided for a bucket in which a door is coupled to a body of the bucket at a pivot mount. The linkage assembly includes a first link, a second link, and a snubber. The first link is pivotally coupled to the body and disposed in a spaced-apart relation to the pivot mount. The second link is pivotally coupled to the door and disposed in a spaced-apart relation to the pivot mount. The first and second links are also pivotally coupled together at a link pivot. The snubber is disposed between the pivot mount and the first link.

TECHNICAL FIELD

The present disclosure generally relates to a snubber for a dipper door. More particularly, the present disclosure relates to a snubber for a dipper having a body and a movable door coupled to the body.

BACKGROUND

Many industrial machines such as rope shovels, diggers, excavators, and the like employ dippers to dig, haul, and transport materials in a given job site. Each of these machines may employ a specific configuration or type of dipper to meet the particular requirements of an application. In the case of a rope shovel, the dipper may typically be configured to have a body and a door that is pivotally coupled to the body so as to allow a swinging movement of the door in relation to the body. If the door is allowed to swing freely it can slam into the body which has a deleterious effect on the working life of the dipper.

Numerous designs and mechanisms of linkages have been developed by various manufacturers of such industrial machines to allow the swinging movement of the door for accomplishing an opening and closing of the door with respect to the body of the bucket.

U.S. Pat. No. 6,467,202 discloses a dipper door that is pivotally mounted to a dipper. In one embodiment the door is pivotally mounted to the dipper by a pin, and the door is controlled by a linkage actuated by a linear actuator to control the opening and closing of the door.

SUMMARY OF THE DISCLOSURE

In one aspect of the present disclosure, a snubber for a dipper door is provided. The snubber comprises a five bar linkage including a linear actuator, the linear actuator being configured to provide resistive force to the dipper door via the linkage assembly when the door is closing.

In yet another aspect of the present disclosure, a linkage assembly for a door coupled to a body at a pivot mount is provided. The linkage assembly comprising a first link, a second link, and a linear actuator. The first link is pivotally coupled to the body spaced from the pivot mount. The second link is pivotally coupled to the door spaced from the pivot mount, and the first and second links pivotally coupled together at a link pivot. The linear actuator is provided between the pivot mount and the first link.

In yet another aspect of the present disclosure, a method of controlling angular movement of a door relative to a body to which the door is coupled at a pivot mount is provided. The method includes pivotally coupling a first link to the body, pivotally coupling a second link to the door, and pivotally coupling the first and second links together. A resistive force is provided to the first link remote from where the first link is pivotally coupled to the body.

Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like reference numbers indicate identical or functionally similar elements.

FIG. 1 is a side view of an exemplary machine showing a bucket in which embodiments of the present disclosure can be implemented;

FIG. 2 is a perspective view of the bucket showing a linkage assembly, in accordance with embodiments of the present disclosure;

FIG. 3 is a side view of the bucket from FIG. 2 showing the linkage assembly, in accordance with embodiments of the present disclosure;

FIG. 4 is a schematic of a 5-bar linkage mechanism formed using components of the linkage assembly from FIG. 3 in accordance with embodiments of the present disclosure;

FIG. 5 is a graph depicting a comparison between resistive forces and torques required by a conventional 3-bar linkage mechanism, a conventional 4-bar linkage mechanism with friction brake therein, and the 5-bar linkage mechanism of the present disclosure for preventing a slamming of the door against the body when the door is positioned at various angles in relation to the body of the bucket, in accordance with an exemplary embodiment of this disclosure; and

FIG. 6 is a flowchart depicting a method of controlling angular movement of the door relative to the body, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

The detailed description of exemplary embodiments of the disclosure herein makes reference to the accompanying drawings and figures, which show the exemplary embodiments by way of illustration only. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, it should be understood that other embodiments may be realized and that logical and mechanical changes may be made without departing from the spirit and scope of the disclosure. It will be apparent to a person skilled in the pertinent art that this disclosure can also be employed in a variety of other applications. Thus, the detailed description herein is presented for purposes of illustration only and not of limitation.

With reference to FIG. 1, an exemplary machine 100 is depicted, in which embodiments of the present disclosure may be implemented. As shown, the machine 100 is embodied in the form of an electric rope shovel (ERS) and is shown located on a job site 102. The machine 100 may be used in a variety of applications including mining, quarrying, road construction, construction site preparation, etc. For example, the ERS shown in FIG. 1 may be employed for hauling earth materials such as ore, soil, debris, or other naturally occurring deposits from the job site 102; and for dumping such earth materials at a designated location for e.g., within a container of a truck, or at another designated location on the job site 102.

Although the exemplary machine 100 is embodied as an ERS in the illustrated embodiment of FIG. 1, it will be appreciated that the other types of machines such as, for e.g., but not limited to, diggers, hydraulic excavators, and the like can be optionally used in lieu of the ERS disclosed herein to implement the embodiments of the present disclosure. Moreover, the machine 100 may be a manually operated machine, an autonomous machine, or a machine that is operable in both manual and autonomous mode i.e., a semi-autonomous mode. Therefore, notwithstanding any particular configuration of machine disclosed in this document, it may be noted that embodiments disclosed herein can be similarly applied to various other types and configurations of machines without deviating from the spirit of the present disclosure.

Referring to FIG. 1, the machine 100 may include a frame 106 for supporting thereon—a drive system 108, an articulation system 110, a dipper 112, and multiple ground engaging members which are shown as tracks 114 in FIG. 1. The drive system 108 may include one or more engines (not shown), electric motors for e.g., traction motors (not shown), or both depending on specific requirements of an application. The drive system 108 is configured to produce and transmit output power to the tracks 114 for propelling the machine 100 on the job site 102 and may also be used to transmit output power to the articulation system 110 for performing certain desired functions for e.g., digging, dumping, hauling etc., using the dipper 112 of the machine 100.

In the illustrated embodiment of FIG. 1, the articulation system 110 includes a boom 116, a dipper arm 118, and a saddle 120. As shown, the boom 116 is disposed on the frame 106 while the dipper arm 118 is pivotally and slidably coupled to the boom 116 with the help of the saddle 120. The saddle 120 may allow the dipper arm 118 to be axially displaceable and pivotable along a longitudinal plane AA′ of the machine 100. Moreover, the dipper 112 is coupled to an end 118 a of the dipper arm 118.

Additionally, the articulation system 110 may further include a hoist assembly 122 having cables 124 as shown in the illustrated embodiment of FIG. 1. In the illustrated embodiment of FIG. 1, the cables 124 may be mechanically linked to form endless links, independently or in combination, with one or more pulleys 126 associated with the frame 106, the boom 116, the dipper arm 118, and the dipper 112. Such configuration of the hoist assembly 122 may be generally representative of one or more block and tackle arrangements known to persons skilled in the art. The hoist assembly 122 may then be operated using drive power from the drive system 108 for co-operatively displacing the dipper arm 118 and the dipper 112 axially and/or pivotally with respect to the boom 116.

In alternative embodiments of this disclosure, it is contemplated that the hoist assembly 122 may be implemented using links, ropes or any other structures or mechanisms known to persons skilled in the art. For example, in an alternative configuration, the hoist assembly 122 may be implemented using hydraulic actuators in conjunction with other types of link structures and mechanisms known to one skilled in the art for performing functions that are consistent with the present disclosure.

Further, as shown in the illustrated embodiment of FIG. 2, the dipper 112 includes a body 128, and a door 130 pivotally coupled to the body 128. The door 130 may include at least one mount arm 136 angularly extending therefrom. Two mount arms 136 are shown in the illustrated embodiment of FIG. 2. Each mount arm 136 is pivotally coupled to the body 128 at a first pivot mount 132 as shown in FIG. 2, the first pivot mount 132 being disposed on a top side 128 a of the body 128. The first pivot mount 132 may therefore facilitate angular movement of the door 130 about the body 128 for accomplishing an opening and closing of the door 130 relative to the body 128 of the dipper 112.

The dipper 112 also includes a snubber in the form of a linkage assembly, shown and generally indicated by numeral 138. The linkage assembly 138 is disposed between the body 128 of the dipper 112 and the door 130. The linkage assembly 138 includes a first link 140 and a second link 142. The first link 140 is pivotally coupled to the body 128 and disposed in a spaced-apart relation to the first pivot mount 132. As shown in the illustrated embodiments of FIGS. 2 and 3, a second pivot mount 146 is provided on the top side 128 a of the body 128 and disposed in a spaced-apart relation to the first pivot mount 132 for accomplishing a pivotal coupling of the first link 140 to the body 128 of the dipper 112.

The first link 140 and the second link 142 are pivotally connected at a link pivot 144. As shown in the illustrated embodiment of FIGS. 2 and 3, the link pivot 144 may be embodied in the form of a dowel pin 148 received in a pair of apertures (not shown) defined by each of the first and second links 140, 142. In alternative embodiments, the link pivot 144 disclosed herein may include other structures known to persons skilled in the art for establishing a pivotal connection between the first and second links 140, 142.

An end 142 a of the second link 142 is pivotally coupled to the door 130 at a third pivot mount 150 as shown in FIGS. 2 and 3, the third pivot mount 150 being disposed on a top side 136 a of the mount arm 136. The third pivot mount 150 may therefore facilitate angular movement of the second link 142 about the door 130 for accomplishing an opening and closing of the door 130 relative to the body 128 of the dipper 112. A pair of third pivot mounts 150 are depicted in the illustrated embodiment of FIG. 2 to correspond with the pair of mount arms 136 and the pair of linkage assemblies 138.

Each linkage assembly 138 further includes a linear actuator 152 disposed between the first pivot mount 132 and the first link 140. In one embodiment the linear actuator 152 extends between the first pivot mount 132 and the first link 140 at the link pivot 144. In other embodiments only one linkage assembly 138 may be provided. In a further embodiment the linkage assembly 138 may be provided centrally between the pivot mounts 132.

In the illustrated embodiment of FIGS. 2 and 3, the linear actuator 152 is embodied in the form a hydraulic cylinder having a head end and a rod end. However, in alternative embodiments, the linear actuator 152 may be embodied in the form of other structures known to persons skilled in the art, wherein such other structures are configured to perform functions consistent with embodiments of the present disclosure. Some examples of such structures could include, but is not limited to, a leadscrew or ball screw.

It is hereby envisioned that the door 130 should be held closed while the dipper 112 is being loaded and also while the load in the dipper 112 is swung to a deposit point. At that point, the door 130 should be opened to allow the contents of the dipper 112 to fall out. As such, it may be noted here that while loading, hauling and transporting the load, the door 130 and the body 128 of the dipper 112 are configured to co-operatively prevent the contents in the dipper 112 from falling out of the dipper 112.

The linear actuator 152 of the linkage assembly 138 is configured to operatively resist an angular movement of the door 130 relative to the body 128 vis-à-vis the first and second links 140, 142. As shown in the schematic representation of the linkage assembly 138 in FIG. 4, the first link 140 is pivotally coupled to the second pivot mount 146, the second link 142 is pivotally coupled to the first link 140 with the help of the link pivot 144 while the end 142 a of the second link 142 is pivotally coupled to the third pivot mount 150. Also, the linear actuator 152 is pivotally coupled to the first pivot mount 132 and the first link 140 at the link pivot 144.

In embodiments disclosed herein, it is envisioned that the first link 140 has a length L which is a multiple of a distance D by which the first link's pivotal coupling to the body 128 i.e., the second pivot mount 146 is spaced from the first pivot mount 132, said multiple being in the range of about 0.5 to 1.5. In an example, length L may be 0.7 times the distance D i.e., L=0.7*D. It is envisioned that the length L, being maintained as a multiple of the distance D, also allows control of the angle θ between the linear actuator 152 and the first link 140 while the linear actuator 152 is connected to the first link 140 at the link pivot 144. The length L may therefore, be selected to provide maximum mechanical advantage to the linear actuator 152 for providing resistive force to the first link 140 as angle θ approaches 90 degrees corresponding to the door 130 approaching a closing position with respect to the body 128.

Moreover, in a further embodiment of this disclosure, it may be additionally or optionally contemplated to shape the second link 142 in a way such that the second link 142 provides a clearance between the second link 142 and the linear actuator 152. As shown in the illustrated embodiments of FIGS. 2 and 3, the second link 142 may be formed to exhibit an arcuate shape as shown in FIGS. 2 and 3 so that the second link 142 is configured to provide clearance between the second link 142 and the linear actuator 152. The clearance disclosed herein may aid in preventing an interference between the second link 142 and the co-located linear actuator 152 during an operation of the linkage assembly 138 and hence, facilitate an unobstructed movement of the second link 142 in relation to the linear actuator 152.

Referring again to FIG. 3, it is hereby envisioned that the first link 140, the second link 142, the door 130, the body 128 and the linear actuator 152 define a 5-bar linkage mechanism. Specifically, as shown in the schematic of FIG. 4, the first link 140, the second link 142, the mount arm 136 of the door 130 and the linear actuator 152 together with the first pivot mount 132, the second pivot mount 146, the third pivot mount 150, and the link pivot 144 define a 5-bar linkage mechanism. Hence, for the purposes of this disclosure, it may be noted that the linkage assembly 138 disclosed herein is representative of a 5-bar linkage mechanism.

As disclosed earlier herein, an angular motion of the door 130, the second link 142, and the first link 140 relative to the second pivot mount 146 may be restricted by the linear actuator 152 while the door 130 is closing in on the body 128 of the dipper 112. In an embodiment herein, the linear actuator 152 is configured to provide resistive force when a closing angle α between the door and the body is preferably in the range of about 0 to 30 degrees. It will be appreciated by those skilled in the art that the snubber disclosed herein is beneficially configured to provide the resistive force to the door 130 as the door 130 is nearing the body 128 of the dipper 112 to prevent or at least reduce slamming of the door and such resistive force from the snubber may be easily facilitated by providing the first and second links 140, 142 and by virtue of the first and second links 140, 142 being able to pivot about the link pivot 144.

Moreover, in embodiments disclosed herein, it is envisioned that when the door 130 is in a closed position, an angle θ between the linear actuator 152 and the first link 140 is in the range of about 60 to 90 degrees depending on a configuration of the given linkage assembly 138. For example, in one exemplary configuration of the linkage assembly 138, the angle θ between the linear actuator 152 and the first link 140 may be 70 degrees when the door 130 is in the closed position. In another exemplary configuration of the linkage assembly 138, the angle θ between the linear actuator 152 and the first link 140 may be 80 degrees when the door 130 is in the closed position. In a preferred embodiment, the linear actuator 152 would be configured in a substantially perpendicular position (i.e., approx. or equal to 90 degrees) with respect to the first link 140 when the door 130 is in a closed position.

Referring to FIG. 5, a graph 500 depicting a comparison between resistive forces and torques typically required by a conventional 3-bar linkage mechanism (not shown), a conventional 4-bar linkage mechanism with a friction brake (not shown), and the 5-bar linkage mechanism of the present disclosure (i.e., the linkage assembly 138 disclosed herein) for preventing a slamming of the door 130 against the body 128 when the door 130 is positioned at various angles in relation to the body 128 of the dipper 112, in accordance with an exemplary embodiment of this disclosure.

It may be seen that an amount of resistive force needed with use of the present linkage assembly 138 is significantly lower than the resistive force needed with use of the conventional 3-bar linkage mechanism when the door is positioned at relatively small angles α with respect to the body 128 of the dipper 112, wherein such small angles α0 lie in the range of 0 to 30 degrees as shown in FIG. 5 and disclosed in a preferred embodiment earlier herein. Such lesser force requirements associated with the 5-bar linkage mechanism i.e., the linkage assembly 138 may help in prolonging a service life of components in the linkage assembly 138, and more specifically, help prolong a service life of the linear actuator 152 disclosed herein.

Various embodiments disclosed herein are to be taken in the illustrative and explanatory sense, and should in no way be construed as limiting of the present disclosure. All numerical terms, such as, but not limited to, “first”, “second”, “third”, or any other ordinary and/or numerical terms, should also be taken only as identifiers, to assist the reader's understanding of the various embodiments, variations, components, and/or modifications of the present disclosure, and may not create any limitations, particularly as to the order, or preference, of any embodiment, variation, component and/or modification relative to, or over, another embodiment, variation, component and/or modification.

It is to be understood that individual features shown or described for one embodiment may be combined with individual features shown or described for another embodiment. The above described implementation does not in any way limit the scope of the present disclosure. Therefore, it is to be understood although some features are shown or described to illustrate the use of the present disclosure in the context of functional segments, such features may be omitted from the scope of the present disclosure without departing from the spirit of the present disclosure as defined in the appended claims.

INDUSTRIAL APPLICABILITY

FIG. 6 is a flowchart illustrating a method 600 for controlling an angular movement of the door 130 relative to the body 128 while the door 130 remains coupled to the body 128 at the first pivot mount 132. At step 602, the method 600 includes pivotally coupling the first link 140 to the body 128. At step 604, the method 600 further includes pivotally coupling the second link 142 to the door 130.

At step 606, the method 600 further includes pivotally coupling the first and second links 140, 142 together at the link pivot 144. At step 608, the method further includes providing resistive force to the first link 140 remote from where the first link 140 is pivotally coupled to the body 128. As disclosed earlier herein, each of the second pivot mount 146 and the link pivot 144 are spaced apart from the first pivot mount 132 at which the first link 140 is pivotally coupled to the body 128.

As disclosed in embodiments herein, the linear actuator 152 is configured to offer resistive force to a closing movement of the door when a closing angle α between the door 130 and the body 128 is in the range of about 0 to 30 degrees. Moreover, such resistive force is provided by the linear actuator 152 when the snubber is substantially perpendicularly to the first link. In a preferred embodiment, the linear actuator 152 would be configured to remain in a substantially perpendicular position (i.e., approx. or equal to 90 degrees) with respect to the first link 140 when the door 130 is in a closed position.

Embodiments of the present disclosure have applicability for use and implementation in controlling an angular movement of the door 130 relative to the body 128 of the dipper 112. Although embodiments of the present disclosure are implemented in conjunction with the dipper 112 of the exemplary machine 100 i.e., the ERS, buckets typically used on other types of machines such as, but not limited to, diggers, hydraulic excavators, and the like may be optionally used to implement the embodiments herein.

With implementation of embodiments disclosed herein, the angular movement of the door 130 may be controlled using a reduced or minimal amount of force and/or torque from the linear actuator 152, due at least in part, to the configuration of the first and second links 140, 142 present in the linkage assembly 138 disclosed herein. As the linkage assembly 138 is configured to represent a 5-bar linkage mechanism and by virtue of the first and second links 140, 142 being pivotally operable about the link pivot 144, a length of travel i.e., compression executed by the linear actuator 152 when the door 130 is in the range of 30 degrees or lesser with respect to the body 128 beneficially helps the linear actuator 152 to offer resistive force to the door 130 when the door 130 is nearing the body 128 and hence, decelerate a movement of the door 130 as the door 130 is closing in on the body 128. Therefore, embodiments disclosed herein can beneficially help in preventing the door 130 from slamming against the body 128 of the dipper 112 after a dumping operation is completed or prior to initiation of a digging cycle.

While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof. 

What is claimed is:
 1. A snubber for a dipper door, comprising: a five bar linkage including a linear actuator; the linear actuator configured to provide resistive force to the dipper door via the linkage assembly when the door is closing.
 2. The snubber of claim 1, wherein the dipper door is pivotally coupled to a dipper body at a pivot mount, the five bar linkage including: a first link pivotally coupled to the dipper body spaced from the pivot mount; a second link pivotally coupled to the dipper door spaced from the pivot mount, the first and second links pivotally coupled together at a link pivot; wherein the linear actuator is provided between the pivot mount and the first link.
 3. The snubber of claim 2, wherein the linear actuator is provided at the first link proximate the link pivot.
 4. The snubber of claim 2, wherein an angle between the linear actuator and the first link when the dipper door is in a closed position is in the range of about 60 to 90 degrees.
 5. The snubber of claim 4, wherein the linear actuator is substantially perpendicular to the first link when the door is in a closed position.
 6. The snubber of claim 1, wherein the linear actuator is configured to provide resistive force when a closing angle between the dipper door and a dipper body is in the range of about 0 to 30 degrees.
 7. The snubber of claim 1, wherein the linear actuator comprises a hydraulic cylinder.
 8. A linkage assembly for a door coupled to a body at a pivot mount, the comprising: a first link pivotally coupled to the body spaced from the pivot mount; a second link pivotally coupled to the door spaced from the pivot mount, the first and second links pivotally coupled together at a link pivot; and a linear actuator provided between the pivot mount and the first link.
 9. The linkage assembly of claim 8, wherein an angle between the linear actuator and the first link when the door is in a closed position is in the range of about 60 to 90 degrees.
 10. The linkage assembly of claim 9, wherein the linear actuator is substantially perpendicular to the first link when the door is in a closed position.
 11. The linkage assembly of claim 8, wherein the first link has a length which is a multiple of a distance by which the first link's pivotal coupling to the body is spaced from the pivot mount, said multiple being in the range of about 0.5 to 1.5.
 12. The linkage assembly of claim 8, wherein the linear actuator is configured to provide resistive force when a closing angle between the door and the body is in the range of about 0 to 30 degrees.
 13. The linkage assembly of claim 8, wherein the linear actuator comprises a hydraulic cylinder.
 14. The linkage assembly of claim 8, wherein the linear actuator is provided at the first link proximate the link pivot.
 15. The linkage assembly of claim 8, wherein the first link, the second link, the door, the body and the linear actuator define a 5-bar linkage mechanism.
 16. A method of controlling angular movement of a door relative to a body to which the door is coupled at a pivot mount, the method comprising: pivotally coupling a first link to the body; pivotally coupling a second link to the door; pivotally coupling the first and second links together; and providing resistive force to the first link remote from where the first link is pivotally coupled to the body.
 17. The method of claim 16, wherein resistive force is provided when a closing angle between the door and the body is in the range of about 0 to 30 degrees.
 18. The method of claim 17, wherein resistive force is provided substantially perpendicularly to the first link. 